The continuous improvement of the performance and miniaturization of the sensors followed by their increased connectivity have triggered the development of the Internet of Things (IoT) for consumer applications. It is now the time for industrial IoT, where intelligent components will be used for connecting manufacturing lines, homes, hospitals, buildings, airports and workers to the Internet and thus, a real time (management) decision/can be obtained by analyzing big volumes of data provided by sensors and sensor networks. Connected workers working in a harsh environment (i.e. toxic and flammable gases ambient) may benefit from networked toxic gas sensors. However, current gas sensors consume significant amounts of power, making it difficult to be integrated in such a network.
Current gas sensors for toxic and flammable gases based on metal oxides, employing either calorimetric or chemoresistive detection principles, require high electric power consumption levels (100-200 mW), making them unsuitable for networked operation. Microelectromechanical systems (MEMS)-based gas sensors are currently emerging as commercial products with lower power consumption levels envisaged for their operation. However, even the announced minimum power consumption level for these structures (15 mW when operated in pulse width modulation) is still high enough to prevent their integration in wide, IoT-connected networks.